{"_id":"560d769505b3941700338762","project":"560c93ad7e9b9d0d00ca81a2","version":{"_id":"560c93ae7e9b9d0d00ca81a5","project":"560c93ad7e9b9d0d00ca81a2","__v":9,"createdAt":"2015-10-01T02:00:14.709Z","releaseDate":"2015-10-01T02:00:14.709Z","categories":["560c93af7e9b9d0d00ca81a6","560c9d9399bb5a0d0044f220","560d76d899bb5a0d0044f307","560d76ee1ec45619006069ed","560d86e099bb5a0d0044f32e","560dba80373c0e0d0024ff3b","57c722ecdf19130e001fba5d","57c743d1b6f94a2200659903","58995ec083f743190077bbe2"],"is_deprecated":false,"is_hidden":false,"is_beta":false,"is_stable":true,"codename":"","version_clean":"1.0.0","version":"1.0"},"category":{"_id":"560c9d9399bb5a0d0044f220","pages":["560ca0517048021700e180e6","560d6190af9723190093812c","560d74751ec45619006069e9","560d769505b3941700338762"],"project":"560c93ad7e9b9d0d00ca81a2","version":"560c93ae7e9b9d0d00ca81a5","__v":4,"sync":{"url":"","isSync":false},"reference":true,"createdAt":"2015-10-01T02:42:27.154Z","from_sync":false,"order":0,"slug":"javascript-api-client-side","title":"JavaScript API (client-side)"},"githubsync":"","user":"560c92f2ac2859170013faa3","__v":1,"editedParams":true,"editedParams2":true,"parentDoc":null,"updates":[],"next":{"pages":[],"description":""},"createdAt":"2015-10-01T18:08:21.010Z","link_external":false,"link_url":"","sync_unique":"","hidden":false,"api":{"settings":"","results":{"codes":[]},"examples":{"codes":[{"name":"","code":"Attribution.track(event, [properties], [callback]);","language":"javascript"}]},"auth":"required","params":[{"_id":"560ca0517048021700e180e9","ref":"","in":"body","required":true,"desc":"The name of the event","default":"","type":"string","name":"event"},{"_id":"560ca0517048021700e180e8","ref":"","in":"body","required":false,"desc":"A hashtable of properties describing the event.","default":"","type":"object","name":"properties"},{"_id":"560ca0517048021700e180e7","ref":"","in":"body","required":false,"desc":"A callback function that gets called after a short timeout.","default":"","type":"object","name":"callback"}],"url":"/Attribution.track(event, [properties], [callback]);"},"isReference":true,"order":3,"body":"There are two main use cases for \"alias\" method:\n\n1) used to when you really want to merge two use data into one, this could be if your user moved/created new account (for example due to technical issues) but you still want to see the whole hist history as one user.\n\n2) you are doing \"identify\" call only on server-side. In this case would need **previousId** parameter to be Anonymous ID which you can access from JS snippet by calling **Attribution.user().anonymousId();** (this method is not recommended unless you have specific needs and understand what you are doing).\n[block:code]\n{\n  \"codes\": [\n    {\n      \"code\": \"Attribution.alias([userId], [previousId], [callback]);\",\n      \"language\": \"javascript\"\n    }\n  ]\n}\n[/block]\n\n[block:parameters]\n{\n  \"data\": {\n    \"0-0\": \"**userId **\\n*String, required*\",\n    \"0-1\": \"The new User ID you want to associate the user with.\",\n    \"1-0\": \"**previousId **\\n*String, required*\",\n    \"1-1\": \"The previous ID that the user was recognized by.\",\n    \"2-1\": \"A callback function that gets called after a short timeout.\",\n    \"2-0\": \"**callback **\\n*Object, optional*\"\n  },\n  \"cols\": 2,\n  \"rows\": 3\n}\n[/block]\n\n[block:code]\n{\n  \"codes\": [\n    {\n      \"code\": \"Attribution.alias('00812938', '00812939');\",\n      \"language\": \"javascript\"\n    }\n  ]\n}\n[/block]","excerpt":"alias is used to merge two user identities, effectively connecting two sets of user data as one. It is an advanced method and is not necessary for most integrations.","slug":"alias","type":"fn","title":"Alias"}